Microsoft has made the source code of ASP.NET MVC available under an open source license since the first V1 release. We’ve also integrated a number of great open source technologies into the product, and now ship jQuery, jQuery UI, jQuery Mobile, jQuery Validation, Modernizr.js, NuGet, Knockout.js and JSON.NET as part of it.

I’m very excited to announce today that we will also release the source code for ASP.NET Web API and ASP.NET Web Pages (aka Razor) under an open source license (Apache 2.0), and that we will increase the development transparency of all three projects by hosting their code repositories on CodePlex (using the new Git support announced last week). Doing so will enable a more open development model where everyone in the community will be able to engage and provide feedback on code checkins, bug-fixes, new feature development, and build and test the products on a daily basis using the most up-to-date version of the source code and tests.

We will also for the first time allow developers outside of Microsoft to submit patches and code contributions that the Microsoft development team will review for potential inclusion in the products. We announced a similar open development approach with the Windows Azure SDK last December, and have found it to be a great way to build an even tighter feedback loop with developers – and ultimately deliver even better products as a result.

Very importantly - ASP.NET MVC, Web API and Razor will continue to be fully supported Microsoft products that ship both standalone as well as part of Visual Studio (the same as they do today). They will also continue to be staffed by the same Microsoft developers that build them today (in fact, we have more Microsoft developers working on the ASP.NET team now than ever before). Our goal with today’s announcement is to increase the feedback loop on the products even more, and allow us to deliver even better products. We are really excited about the improvements this will bring.

The Git repository on the site is the live RC milestone development tree that the team has been working on the last several weeks, and the tree contains both the runtime sources + tests, and is buildable and testable by anyone. Because the binaries produced are bin-deployable, this allows you to compile your own builds and try product updates out as soon as they are checked-in.

You can also now contribute directly to the development of the products by reviewing and sending feedback on code checkins, submitting bugs and helping us verify fixes as they are checked in, suggesting and giving feedback on new features as they are implemented, as well as by submitting code fixes or code contributions of your own. Note that all code submissions will be rigorously reviewed and tested by the ASP.NET MVC Team, and only those that meet an extremely high bar for both quality and design/roadmap appropriateness will be merged into the source.